Nuprl Lemma : ss-open-and_wf

∀[X:SeparationSpace]. ∀[A,B:Open(X)].  (A ⋂ B ∈ Open(X))


Proof




Definitions occuring in Statement :  ss-open-and: A ⋂ B,  ss-open: Open(X),  separation-space: SeparationSpace,  uall: ∀[x:A]. B[x],  member: t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  ss-open-and: A ⋂ B,  so_lambda: λ2x.t[x],  prop: ℙ,  and: P ∧ Q,  ss-open: Open(X),  subtype_rel: A ⊆r B,  so_apply: x[s]
Lemmas referenced :  exists_wf,  ss-basic_wf,  subtype_rel_self,  equal_wf,  ss-basic-and_wf,  ss-open_wf,  separation-space_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  lambdaEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  productEquality,  applyEquality,  instantiate,  universeEquality,  because_Cache,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality

Latex:
\mforall{}[X:SeparationSpace].  \mforall{}[A,B:Open(X)].    (A  \mcap{}  B  \mmember{}  Open(X))



Date html generated: 2020_05_20-PM-01_22_35
Last ObjectModification: 2018_07_06-PM-04_49_20

Theory : intuitionistic!topology


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